Ketones, Ketosis, and Ketogenic Diets

An understanding of ketones and ketosis is essential for
understanding how some high protein-low carbohydrate diets (also called Ketogenic Diets) such as Atkins diet works.

Ketones are mild acids, a sort of reserve fuel released from burned fats for survival under conditions of starvation. When we go without food for even a few days our bodies begin living off our stored fats, and these release
ketones.

During ketosis, the body switches from using glucose for energy (sufficient dietary
carbohydrates are not available) to using fat. Fatty acids are then released into the bloodstream and converted into
ketones. The ketones themselves are produced by the metabolism of fat.

Ketosis refers to the process of the conversion. The ketones are used by your muscles, your brain, and other organs as an energy source. Excess ketones are then eliminated during urination.

Ketosis occurs when the amount of carbohydrate fuel- the fuel that is needed to run the body - drops below a critical level, forcing the body to turn first to protein and then to fat reserves to do the work carbohydrates normally do. When protein is deflected in this manner, it releases nitrogen into the blood stream, placing a burden on the kidneys as they try to excrete excessive urinary water due to sodium loss. When fat is likewise deflected, the breakup releases fatty acids, or ketones, into the bloodstream, further burdening the kidneys. If ketosis continues for long periods of time, serious damage to the liver and kidneys can occur, which is why most low-carbohydrate, or ketogenic diets recommend only short-term use, typically 14 days. Many nutritionists caution their patients-especially women in the early stages of pregnancy-against following them at all.

Fasters experience a sensation of improved well-being and absence of bothersome hunger in the second or third day of a fast. Experts suggest that this feeling is due to a chain of reactions set off by the release of ketones. Ketones inhibit the release of insulin and the stress hormones. As a result, the blood sugar becomes more stable and hunger is calmed. Anxiety is reduced.

During ketosis the brain cells are calmed down enough to prevent epileptic seizures. The electrical activity of the brain, as measured on an electroencephalogram (EEG), is found to improve in regularity and intensity. Ketones, being acids, also tend to sterilize the urine against infection. They even dissolve certain types of kidney stones.

The low-carbohydrate diets that rely on ketosis for weight loss are termed ketogenetic diets. There is no question that ketogenic diets work. They can result in quick weight loss. Dr. Atkins' diet is and example of a diet based on ketosis produced by a very low carbohydrate intake.

There are several disadvantages and dangers of ketogenic diets. The most significant danger is the risk associated with ketosis itself. Pregnant women, alcoholics, or persons suffering from kidney or liver disease should never undertake a ketogenic diet.

Other side effects associated with ketogenic diets include temporary dizziness, headache, lethargy, weakness and, in extremis, diarrhea and nausea. In addition, a person on a diet extremely low in carbohydrates, fiber, and many vitamins and minerals is liable to feel cranky, sluggish, and deprived.

There are individual differences in the ability to tolerate the ketosis. More than half the people experience fatigue and mental dullness at the onset of ketosis. Some want to give up at once.

Even without reaching ketosis to the point where ketones appear in the urine, insulin activity is reduced and the formation of fat in the cells is slowed.

Lean people in particular have a poor tolerance for too low carbohydrates in the diet. A good measure of whether you should continue such a diet is how well you can keep your se1se of humor. If you're overweight to begin with, the chances are you'll be able to smile through four or five days on less than 30 grams of carbohydrates. Above this level is a transition point, what Dr. Atkins calls the "critical carbohydrate level," for at 60 grams of carbohydrate a day most people no longer are in ketosis. For majority of dieters, this level is associated with feelings of well-being. It is optimal.

It appears that the dieters can attain their nirvana without going full blast on ketosis, unless there is some medical reasons for quick weight loss. Diets such as South Beach Diet allow some complex carbohydrate intake to prevent the dangers of ketosis.

Sources:

Mega Mega Nutrition by Richard A. Kunin MD
Eat Better, Live Better: A Common sense Guide to Nutrition and Good Health by Readers Digest